1. Field of the Invention
The present invention relates to an actuator powered apparatus that has application for clamping, welding and other assembly functions that are common in the manufacture and assembly of vehicles, such as automobiles. More particularly, the invention is related to a dual action actuator powered apparatus that is equipped with two elongate arms that are spaced apart from one another. The elongate arms each have a rack gear that meshes with a pinion gear that is interengaged with both rack gears. The elongate arms are positioned within a common housing that supports fluid driven cylinders that are attached to each elongate arm.
2. Description of the Prior Art
The prior art discloses a variety of devices that employ the rack and gear combination to change arcuate motion to a translatory function, or vice versa. In general, most of the prior art devices utilize the pinion gear shaft to supply power to the device or else take power out via the pinion shaft. The prior art devices employ a rack gear that is formed from plate or bar stock as well as a cylindrical rod.
The present invention differs from the rack and pinion gear driven load grip device that is shown and described in U.S. Pat. No. 2,595,131 entitled "Load Grip Means for Trucks and the Like" issued Apr. 29, 1952, to Leslie G. Ehmann. FIG. 1 of the Ehmann patent depicts a pair of spaced apart cylinders 26 that are oriented parallel to one other. In cross section, the cylinders are square in configuration and have a cylindrical bore located along the longitudinal axis of the cylinder. One of the four sides of each cylinder contains a rack gear. The rack gears of the cylinders mesh with the teeth of a pinion gear that is attached to a flange. Each one of the cylinders is powered by a piston that is connected to a piston rod. The piston and the piston rod are contained within the cylinder in the usual fashion, with only the end of the piston rod protruding from the cylinder. The ends of the piston rods are fixed, thus, when fluid pressure is applied to the piston head, the cylinder with its attached rack gear moves in a linear direction. The pinion gear is fixed against rotation by its attached flange. Consequently, when fluid pressure is applied to the piston heads, the rack gear containing cylinders walk around the teeth of the fixed pinion gear. In this manner, a torque is developed to rotate the entire plate t which the cylinders and their accompanying pistons are attached.
The present invention differs from the above described device in that the power generating fluid driven cylinders are separate from the rods or elongated arms that contain the rack gear teeth. Thus, any malfunction of the piston head, or its seals, does not affect the block assembly that houses the elongated arms.
In U.S. Pat. No. 3,018,885 entitled "Extrusion and Stretch-Straightening Apparatus and Method" issued Jan. 30, 1962, to Leonard H. Trautman, there is shown an apparatus for stretching a metal rod subsequent to its formation by an extrusion process. The metal rod is grasped at both ends and then elongated to remove any non-linear sections that ma have resulted because of the extrusion process. The grasping of the rod is achieved by a pair of jaws that move into engagement with opposed sides of the rod. As shown in FIG. 3 of the drawings, the jaws are each attached to an elongated bar that has a rack gear formed on the end of the bar that is remote from the clamp jaw. The rack gears are positioned opposed to one another in spaced apart relationship with an idler pinion gear positioned therebetween. One of the elongate bars is attached to a fluid driven cylinder 42. The reciprocating action of the fluid cylinder 42 causes the jaws, which are attached to the elongate bars, to move into and out of engagement with the workpiece.
Thus, the present invention differs from the previously described metal stretching apparatus in that the elongate arms are linear in configuration and are confined within a block that has precisely aligned grooves.
In a somewhat similar application, the rack and pinion gear assembly shown in FIG. 5 of U.S. Pat. No. 3,752,062 entitled "Apparatus for Bonding Brake Linings" issued Aug. 14, 1973, to Thomas E. Morgan, Sr. et al, utilizes a pair of opposed elongated rods to control the movement of bars 134 and 136. The elongated rods each have rack gears that engage a common idler pinion gear. A lever having a centrally disposed fulcrum is attached to an end of one elongated rod. The lever is also attached to a fluid driven cylinder 168. Thus, movement of the actuator rod in the fluid driven cylinder 168 will cause the attached elongated rod and rack gear to move in the opposite direction. The present invention is an improvement over the aforementioned apparatus in that there is no lever arm positioned between the fluid driven cylinder and the rack gear. Then, too, the present invention provides for rapid disengagement of the cylinder rod from the rack gear assembly.